Thread holder and trimmer for buttonhole sewing machines



25, 1931- A. F. CARLSON 1,820,557

THREAD HOLDER AND TRIMMER'FOR BUTTONHOLE SEWING MACHINES Filed March 21, 1928 V15 Sheets-Sheet 1' =0 l w 0-: f w A T w 1 l i m 5 LO I r o g o i 0 m 1 r 00 m an o r LO 8 InvenTor.

Axel F Carlson AITys.

Aug. 25, 1931. A. F., CARLSON 1,820,557

THREAD HOLDER AND TRIMMER FOR BUTTONHOLE SEWING BACHINES Filed March 21'. 192B :5 Sheets-Sheet 2 Fig-Z lnvenTor.

, Axel F Carlson byWMkM ATTys.

Aug. 25,1931. A; F. CARLSON THREAD HOLDER AND TRIMMER FOR BUTTONHOLE SEWING IAGHINES a Shets-Sheet :5

Filed Mafch 21. 1928 lnvenTor. Axel F Carlson ATTy s.

Patented Aug. 25, 1931 AXEI; cAnLson, 0F cemnnmemmnesmnusmms; nssmnon 'mf'rm nnlcminumom HOLE MACHINE COMPANY, 011 BOSTON; MASSACHUSETTS; AA. oonmmmomor;

THREAD 1101mm" AND TBIMMEBQFOR' nurzromione smmemhcnnmsi Application filed MarehQl,

This invention relates to" buttonhole sewingmachines of that type which are equipped with means-for cutting the underthre'ad at the end of the buttonhole and' for holding the severed end' until the first stitches have been formed'on" the next succeedingbuttonhole.

The object of the invention is to provide an improved means'for thusholding the out 0 end of" thread and subsequently releasing said end afterthe firststitchesofthe buttonhole' have b'een formed. r In order to give an understanding of" the inventionI have illustrated-in the drawings some selected embodiments thereof which Will now be" descrihedlafterz which I the novel features will bepointed out in the appended claimsuv Fig. 1 is asideviewvoflashuttonhole sew-- "-26 ing machine embodying my invention;

Fig." 2- isa; fragmentary plan view ofthe work "support showing" the cutter fortthe derthi'ead Fig; 3 is: an" under side view of the'worksupport illustrating the thread ho'lder;

Fig. 4'is azrfregm'entary edge view' of the thread holder;

Fig. 5 a viewmfthethread ho1derde=- fetched from its actuatingniechwnismg F 1g.- 6- is a view illustrating"the manner in which thethreaid ent'ers thetiireadFgrip per;

Fig. 7 is a view similer to Fig; 3 showings; difier'ent embodiment of the invention;

8 is a fragmentary View? showing" the thread holder: in Fig 7" pened fOrreleasing the-thread} y FigI'Q-is an enltfged-seetiononthe line 9- 9,l fig. 71 I e V I have chosen herein-to illustrate my invention as it might be embodied in the sew in'g machine of the type shown in my 'Pa-tents #3705944, hfiitfch1 and $1,771} 670 July- 29, 1930. i

Referring to-Fi'g 1; 1 indieatesthe frame of "the sewing machine which is 1 provided with the work-supporting 311'! 2' equipped with w clamp plete 3* on'wh ich the workis clamped by means'of suitable work clamps fleshy-reciprocating needle: 'bwr."6 which is The stitch-1fornm ng. mechlzm'ismrt the nsualineedle *5 bywhichxthe upper; is manipulated and which is carriedz in fiver-F mounted in the overhan Tug armfl-of the: frame Lend 1InderithreaS XneBhMdSnI- 'MI may be inthe form'ofthe-usedl bobbin ing the under thread and a rotary hoolismssmciated I therewith by which: the underthread are concatenated;

' The work-supporting plate-3i is provided with the Usual sewingopeningmmthmefi 8i through which the needle 5 1 The stitch-forming mechsnismiis V byany suitable means trom theidi'ivin ehwfitig q; 90 which in turn is driven from the em pulley 10 through any appropriate:- ch -15c device'; g

The parts which havethus beem referred'to are or'may'be ofsanyfisuitableioi'i usuwl construction and form no: part of my;

p resent invention; which re'l 'lates v rticularly to the meansforholdingthe '1 orfi' t'heiu'm' V derkthread after it"h asbeen1cm, at thesmm pletion of e butonhole. When theisewing on the bnttonhole is completed end the ma chine is brought" to restthe usual motion, theunder thread;; which extends from the work to the bobbin; is: cut beneatli the work and closetothe work. This ting is doneby means-of ethread cutt'erfil (seeFig: 2) which-iscon'etruct'ed ated similar tothe threadeutter show-n dir my patent #l*,705-,044," March-12; 1929 The thread cutter is situated seamen plate 3 'b'ut operates beneath the work; lt isi provided at its forward end" with a2. cutting edge "10 and is pi-votally connected at its T8921? end as shown at 11 to e block liwhich issiid able in a guideway-1.3formedin tlie iplateifi: The cutting bla le =9ihas' a= pin 1=4dependiiig therefrom which; operates en -incl'ined slbt 15f0rmed in theplete 3, the construction being such that when' the"slide l iswma'vedfi forwardly the cutting knife will: be i both a forward moveinentsand lailseia pmtti swinging movementytherehyato carrytheeut ting edge. 10 across the. sewing: opening) 851 Duringqthisf movement the cutting of? the knife will engage the under thread; lead? ing from the work through the sewing opening and will sever the latter close to the work all as described in my above-mentioned Patent 1,705,044. 7

The, means employed for operating the slide 12 'andlthe knite'9 are similar to those shown in my co-pending applications. This slide 12 is connected to a block 16 situated on the under side of the plate 3 by suitable connections' which extend through and operate in the slot 17 formed in said plate so that the slide 12and block 16 constitute a rigid unit.

The block 16'is provided with a depending pin 18 which is adapted to be engaged by a finger 19 extending from a slide or bar 20 situated; on-"the under side of the plate 3 and movable longitudinally of the buttonhole slit. When this slide 20 is'given a movement teward the right in Fig. 1 or upwardly in Fig. 3jthe tinger19 will engage the pin 18 and thereby. give the slide 12 itsoperative movement :to cause the cutter 9 to cut the lower thread. 1 .fThiS actuating slide 20 is given its operative movement upon the completion of t buttonhole by means of a cam device is normally idle during the sewi operation but is rendered operative at t.. completion of ltlle buttonhole all as illustrated in my above-mentioned Patents #1,?059441- and 1,771,670.

, ,"FThe rear end of the slide 20 is provided with an opening through which extends the lower end of anarm 22 pivoted at A3 to the firame' "1, the upper end of said arm having a Slut 24.: therein in which is received a pin 25 carried an arm 26 fast on a rock shaft 27. Said shaft has fast therewith another arm 28;;which bears against the cam 21 and is held in tcontact'therewith by a suitable spring 29. With" this arrangement it will be observed that when the'cam 21 is given its rotation at theend of the buttonhole, in the manner described .in. the above-mentioned. patents, the arms 28, 26 will be rocked and the lever arm 22 willbe swung backwardly thereby givingbackward movement to the slide 20, which backward movement will actuate the under thread''cutter 9. As 'soon as the cam 21 has completedits movement the slide 20 will be returned to its initial position by means of a return-spring 30. The cutter 9 is returned to its normal position by means of an arm 31 which is adapted to engage the pin 18 upon the return movement of the slide 20. V j The under thread holding device with which this invention is particularly concerned, is associated with the slide 20. \Vhen the slide 20 is in its normal or forward posia tion as shownin Fig. 3 there is considerable lost motion between the pin 18 and the linger 19 so that the slide hasazcertain movement before the finger 19 engages the pin 13 to actuate the cutter. The thread-gripping device for the under thread is arranged so that dur ing this initial motion of the slide 20 said gripping device will engage and grip the under thread with the result that when the finger 19 comes in contact with the pin 18 to actuate the cutter the under thread is alreadv gripped between the cutter and the source of supply.

The under thread gripper shown in Fig. 3 comprises two gripping jaws 32 and 33 between which i ie under thread, indicated at is adapted to be gripoed. The jaw 32 is formed on an arm 35 which is rigid with and extends from a plate 36, the latter being adjustably secured to the slide 20. For this purpose the nlate 36 is shown as having a slot 37 through which extends a guiding pin 38 extending from the slide 20 and another slot 39 which receives a clamping screw 10- carried by the slide, thisconstruction pr0- vidingz' for zuljustnu-mt of the plate 36 longitudina y of the slide 20 thereby to provide for ee ting the thread-holding device roperly with reference to the sewing opening and other 'iarts oi? the machine.

The clamping or gripping member 33 is pivotally mounted to the other gripping member as shown at ll and it is acted on by a spring 42 which connects it with the plate 36 and which yieldingly holds it in its operative position or closed relation with reference to the gripping jaw 32. The gripping jaw 33 is guided in its swinging movement partly by the arm 35 and partly by a guiding linger 43, said gripping member operating be tween the arm and the finger.

The parts are shown in Fig. 3 in the position they occupy at the end of the sewing on the buttonhole. Vhen the buttonhole is completed the slide 20 is moved upwardly in Fig. 3 as above described and during the initial upward movement the gripping jaws 32, 33 are carried underneath the sewing opening 8, as shown by the dotted lines in Fig. 3. During this movement the under thread which extends through the sewing opening engages the curved edges &4 of the gripping jaws and is guided thereby between the latter, the jaw 33 swinging backwardly to allow the thread to enter between them as shown in Fig. 6, said thread finding lodgment in the notch 45 of the jaw 32. The spring 42 is a relatively light spring so that the jaws will readily open to receive the thread without placing any undue strain on the thread, the jawsbeing opened by the pressure of the thread thereagainst as they move from the full to the dotted line position, Fig. 3. By-the time the thread has been gripped between the jaws the finger 19 will engage the pin 18 and thereby'actuate the thread cutter 9,'which cuts the under thread between the work and the thread gripper.

After the cutting operation has been performed the slide 20 is returned to its initial position shown in Fig. 3 as above described and? duringz. its return movement the cut end ofiunder thread .34 is held in thegrippingijaws', said thread being. retainedin the jaws until after the stitching has begun on the next succeeding buttonhole.

I have provided herein means whereby as thefirst. stitches are being formed on the next succeeding buttonhole the pivoted jaw 33isopened positively thereby to release the end of-underthread and for this purpose I n have provided herein means actuated by the feedingmovement of the. work clamps.

Whenthe sewing machine is startcd and after the work clamps-.4 have closedonto the work: saidwork clamps are'given a feeding bar-.48 which is moved longitudinally in suit able bearings 49 carried by the work-supporting armc2r The forward'end of the thrust L 1 bar: engagesone'end of a lever 50 which pivoted intermediate of itsends at 51, the other end of said lever carrying a pin 52 adapted to engage a cam face 53 formed on a rearward extension of the pivoted jaw 33.

The lever 50 is acted on by a return spring 54which normally holds it in the position shown inFig. 3. From this construction it will'be seen that when the thrust bar 48 is movedadownwardlyin Fig.3, which will be the motion given to it by the abutment 47 as the stitching on the buttonhole begins, the

lever 50 will be turned about its pivot 51 thus'gcausing the pin 52 to engage thecam face-53 0f the jaw. 33 and swing the latter away from the jaw -32-ther eby releasing the thread which is held between the j aws; Hence the 32 and '33 are actuated at the end of the bu ttonhole to grip the under thread and the jaw32 is-again actuated at the beginning of the button hole to release the thread.

will be disconnected from the abutment "47 as: soon as it has been given a suflicient move inentto' accomplish its function, the abutment 47 being permitted to continue its movement for the length of the buttonhole without further actuating the thrust rod 48. It will be. noted that the rear end of the thrust rod 48 is pivotally mounted to a radius arm 55 which is pivotally mounted at 55 to the work supportingarm 2. By reason of this construction as the thrust rod moves for wardly the rear endthereofwill also swing back o'li from enters and as The thrust rod 48 is so mounted thatit downwardly due toJ-the rotative movement of the radius arm and mentwill withdraw the rear end ofthe thrust rod from engagement with the abutment 47 Y thus leaving the abutmentfreetocontinue its movement.

saiddownward' move- Duringsuch continued forward movement of the abutment over the top of the thrust rod 48 said i abutment will hold the thrust rod from beingv retracted by the spring: 54. Hence as the sewing is in progress the thrust I rod will be held in its forward position so that the jaws will be heldlope-n as shownin dotted lines Fig. 5, such jaws closing. automatically when the buttonhole has been completed andthe abutment-47- has been carried the end ofthe thrustrod.

In Figs. 7 8 and 9 I have illustrated .a slightly dili-erent embodiment of theinven tion. In these figures the two thread-gripping jaws are indicated at 57, 58.. The jaw 57. sl-idably-mountedon the work plate 3 and the aw 5-8 is pivotally mounted tothe jaw 57 as shown at 59. The jaw58 is formed with'a slot GO in which is received a'guid-ing pin 61 carried by theplate 3 and'said jaw is also formed-with an extension. 62. having a slot Gfilthereinin'which is received an? other guiding screw 64 carried by the plate. 3;

in the embodiment shownin Figs. 7; Sand piping jaws are situated on the-op- .ie of-the sewing opening'from what in Fig. 3 but they are given their op-' posit-c i the are erative threadgripping movement by means of the slide 20. This is-accomplish-ed through a lever device 65 which is pivoted to the plate 3 at--('-.6 and one end ofwhich is formed v with a not =h67 inwhich is received apin 68 carried by the slide. At the/other end said lever 6'5 is provi-dedwith'anotch 69 which receives a pin 7 O carried by theextension 62 of the grippingjaw 57. t

Fig. 7 shows the parts intheir normal position, During the initial movement of-the slide the lever 65 will be swung. from the position shown. in Fig. lines Fig. 8, this movement carrying the grippingjaws forwardly to engage the 1111 der thread. j

' The jaw 57 is formed with a thread recei ving notch 71 into which the under thread the gripper moves forward the jaw 58- is swung .backwardly' against thev action of 'ts spring 72 as shown in. Fig.8 so as to permitflthethread to enter between the jaws; This openingmovement ofthe jaw '58 is accomplished by a latch member 73 piv- 7 to that shownin full I cd-to engage the tail 75 0f the jaw58 as the j-awsmove, forward. This operation is clear- 1y shown in Fig. 8. After the under 58 is released and is closedagainstithethread thread has entered the i notch 7 1-between the jaws then the open jaw ing forced by the jaw 58 into the groove 76 formed between the body of the jaw 57 and the lug or extension 77 thereon as clearly seen in Fig. 9 and thereby being normally held.

In order to effect this release of the jaw 58 the latch 73 is formed with a lateral lug 78 which is adapted to he cngaget. by the pin 70 during continued swinging movement of the lever 36 which is illustrated from the full to the dotted line position in Fig. 8 and which occurs as the slide 20 continues its movement. The engt 'cment of the pin T0 with the lug 78 will swing the latch bacicwardly and withdraw it from the tail 75 of the jaw 58 thus allowing the jaw to close.

The end of the lever 35 having the notch 67 is so shaped that when the lever 65 has been carried to the dotted line position Fig. 8 thereby to release the jaw 58 the pin 68 will have been withdrawn from the notch 67 and during further movement of the slide 20 necessary to actuate the thread cutter 9 said pin merely slides along the face 79 of the lever 65. Upon the return movement of the slide the pin 68 will enter notch 67 and will restore the "lever in to its initial position thereby retracting the gripping jaws which at this time hold the cut end of thread.

The spring 72 may be a lativeiy l spring and I have provided an r plying additional. gripping pressure to "vi gripping jaws after they have gripped under thread. and when they in their normal position so that the under thread will be firmly held while the stitching begins on the next buttonhole. This additional pressure is secured through the medium of a spring 81 which encircles the stem 82 of a hook member 83. This stem is slidably mounted in bearings 8a and carries a; collar 85 between which and one of the bearings 84- the spring is situated.

The tail 75 of the jaw 58 is formed with a pin 86 which is adapted to engage the heel: 83 when the jaws are intheir retracted position shown in Fig. 7. As the jaws are carried back'into this retracted position and the pin 86 engages the hook 83 the stem 82 will be drawn hackwardly thus placing the spring 81 under tension with the result that additional gripping force will be applied to the under lllll!(.. The release of this gripping pressure after the first stitches have been formed on the buttonhole is accomplished through the medium of the thrust rod In the construction shown in Fig. 7, however, this thrust rod is adapted to engage one end of a lever 87 pivoted at 88 to the plate 3, the

other end of said lever acting on a pin 89 carried by the slide 20. Hence, when the thrust rod 1-8 is given its operative movement by the abutment 47 as the stitching starts on any buttonhole, the slide 20 will be given a sufficient backward movement to cause the grippers to be moved forwardly to a point where the tail will engage the latch 73 and thereby cause the opening of the aws.

I claim.

1. In two-thread sewing machine, the combination with a stationary frame having a head, of stitch-forming mechanism including a needle and a needle bar vertically re- Cl procating in said head, worleholding means carr d by said frame and movable thereon relative to the stitch-forming mechanism, a cutter for cutting the under hread, a threadgr g nng device, a sliding actuator mounted on the frame, means operated by the initial movement of said actuator to cause the cad-gripping device to grip the under .47 and. by continued movement of said r to cause the cutter to cut the under l between the gripper device and the :2. in a two-thread sewing machine, the romlmia i a stationary frame having tcn-forming mechanism includle and a needle bar vertically rerid head, work-holding means frame and movable thereon itch-forming mechanism, a the under thread, a threadcomprising a pair of relaable gripping jaws, a sliding aced on said frame and means to read-gripping device to grip the cad during the initial movement of the actuator and the cutter to cut the thread sen the gripping device and the work :lna lag continued movement of the actuator. .m. a two-thread sewing machine, the combination with a stationary frame having a head, of stitch-forming mechanism includa needle and a needle bar vertically rerocating in said h ad, work-holding means carried by said frame and movable thereon relative to the stitclrforming mechanism, a cutter for cntt'ng the under thread, a threadgripping device, a sliding actuator mounted on the frame, means to operate said actuator at the end of the buttonhole, and means to cause. the thread-gripping device to grip the under thread during the initial movement of the ac .iator and the cutter to cut the thread between the gripper and the work during continued movement of the actuator. 4:. in a two-thread sewing machine, the combination with a stationary frame having a. head, of stitclrforming mechanism incl 'no; a needle and a needle bar vertically ieciprocating in said head, work-holding means carried by said frame and movable thereon relative to the stitch-forming mechanism, a cutter for cutting the under thread, a thread-gripping device, a sliding actuator mounted on the frame, means to operate said ctuator at the end of the bnttonhole, means to cause the thread-gripping device to grip carried by said frame and movable thereon relative to the stitch-forming mechanism, a cutter for cutting the under thread, a threadgrlpping device compris ng a pa n of relatlvely movable-gripping aws, a sllding actuator mounted on the frame, means to operate the same at the end of the buttonhole, and means rendered Operative by the initial movement of the actuator to cause the threadgripping jaws to grip the under thread and by continued movement of the actuator to cause the cutter to cut said thread between the gripping device and the work.

6. In a two-thread sewing machine, the combination with a stationary frame having ing a needle and a needle bar vei ciprocating in said head, work-hol ding means carried by said frame and movable thereon relative to the stitch-forming mechanism, a cutter for cutting the under thread, a threadgripping device comprising a pair of relatively movable gripping jaws, a sliding actuator mounted on the frame, means to operate the same at the end of the buttonhole, means rendered operative by the initial movement of the actuator to cause the thread-gripping jaws to grip the under thread and by continued movement of the actuator to cause the cutter to cut said thread between the gripping device and the work, and means to open the jaws and release the thread after the next buttonhole has begun.

7. In a buttonhole sewing machine, the combination with a stationary frame having a head, of stitch-forming mechanism including a needle and a needle bar vertically reciprocating in said head, work-holding means mounted on the frame for movement relative to the stitch-forming mechanism, a cutter for cutting the under thread, a threadgripping device, a sliding actuator operated at the end of the buttonhole, means to cause the thread.- gripping device to grip the under thread during the initial movement of said actuator and the cutter to out said thread during continued movement of the actuator, and means operated by said relative movement when the next buttonhole has begun to release the thread from the gripping device.

8. In a buttonhole sewing machine, the combination with a frame, of stitch-forming mechanism carried thereby, a cutter forcutting the under thread, a sliding actuator a head, of stitch-forming mechan sm includally re mounted on the frame, a thread-gripping device carried by the actuator, means to give the actuator its operative movement at the end of the buttonhole, the initial movement thereof causing the gripping device to grip the under thread and continued movement operating the cutter.

9. In a buttonhole sewing machine, the combination with a frame, of stitch-forming mechanismcarried thereby, a cutter for cutting the under thread, a sliding actuator mounted on the frame, a thread-gripping device carried by the actuator and comprising a pair of relatively-movable gripping jaws, means to operate the actuator at the end of the buttonhole, the initial movement of the actuator causing it to grip the under thread and further movement operating the cutter.

10. In a buttonhole sewing machine, the combination with a frame, of stitch-forming mechanism carried thereby, a cutter for cutting the under thread, a sliding actuator mounted on the frame, a thread-gripping device car 'ied by the actuator and comprising a pair of relatively-movable gripping jaws, means to operate the actuator at the end of the buttonhole, the initial movement of the actuator causing it to grip the under thread and further movement operating the cutter, and means to open the jaws and release the thread when the next buttonhole is begun.

11. In a buttonhole sewing machine, the combination with a frame, of stitch-forming mechanism and work-holding means carried thereby but having a relative movement, of a sliding actuator, a thread-gripping device carried by the actuator and having a pair of relatively-movable gripping jaws, means to move the actuator at the end of the buttonhole and thereby cause the thread-gripping device to grip the under thread, and means to open the jaws by said relative movement when the stitching on the next buttonhole is begun.

12. In a buttonhole sewing machine, the combination 7 with stitch-forming mechanism and work-holding means having a relative movement, of a cutter for the under thread, a sliding actuator operated at the end of the buttonhole, a thread-gripping device carried by the actuatorand comprising two relatively-moving gripping jaws. initial movement of the actuator causing the thread-gripping device to grip the under thread, means to cause the cutter to cut thethread during conso I tinued movement of the actuator, and means 

